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HVAC
25
15. TROUBLESHOOTING
A.C .CHECK POINT
SR.
No.
CHECK POINTS
NORMAL CONDITION
RESULTS
A
PASSENGER CABIN
Fresh / recirculation lever
position.
Should be in recirculation
mode.
Will stop entry of hot air from outside.
Air direction knob position.
Should be in face mode.
Will ensure proper cooling
Temperature control lever
position.
Should be in maximum cool
position.
Will ensure that heater is not working
with A.C ON.
Grill direction
Centre grill towards rear
seats.
Will ensure proper distribution of air
in the vehicle.
Side grill towards passenger
& driver seat
B
ENGINE ROOM
Condenser surface
Should be clean and dust /
dirt free.
Will ensure total liquidification of re-
frigerant.
Engine coolant level
Should be on maximum level
Will prevent engine from over heat-
ing.
Engine tuning
Should be as per specifica-
tions.
Will prevent engine room over heat-
ing and increase in fuel consumption.
Belt tension
Belt should not be too loose
or too tight.
Loose belt will slip and affect AC per-
formance
TROUBLE SHOOTING
SR.
NO.
COMPLAINT
POSSIBLE CAUSE
REMEDY
1
Insufficient flow
of cold air
1. Evaporator clogged or frosted.
2. Air leaking from cooling unit or air
duct.
3. Air inlet blocked.
4. Blower motor faulty.
1. Check evaporator.
2. Repair as necessary.
3. Repair as necessary.
4. Replace blower motor.
2
Blower won't
work even
when its switch
is ON
1. Blower fuse blown.
2. Blower motor faulty.
3. Wiring or grounding faulty.
1. Replace fuse.
2. Replace motor.
3. Repair as necessary.
3
Incorrect tem-
perature output
1. Air ducts clogged.
2. Heater matrix leaking or choked.
3. Heater hoses leaking or choked.
4. Kinematics jammed.
1. Repair air ducts.
2. Replace heater matrix.
3. Replace hoses.
4. Repair/Replace kinematics.
4
Cold air comes
out only inter-
mittently
1. Magnetic clutch slipping.
2. AC relay faulty.
3. Expansion valve faulty.
4. Wiring connection faulty.
5. Excessive moisture in the system.
6. Faulty thermister cut-in and/or cut-off
setting.
1. Check magnetic clutch.
2. Replace faulty relay.
3. Check expansion valve.
4. Repair as necessary.
5. Evacuate and charge AC sys-
tem.
6. Replace thermister.